To install a DIY plywood floor won't work as expected, worse if plan replacing an air deck with it. Add power and that combo will rock as a marshmellow due to not having front and side stringers to hold solid the panels in place.
What's is it that deslike about an air floor, needs constant reinflation through the day, it's rigidity ? Saturn sells alum panel floors for that inflatable size call them and inquire what't the asking price. Can bolt to the alum floor whatever you like.
Happy Boating
